Electric tremulant attachment for accordions



Jan. 31, 1939. v L H 2,145,530

ELECTRIC TREMULANT ATTACHMENT FOR ACGORDIONS Filed Aug. 9, 1957 2Sheets-Sheet 1 amen V1304,

Zeste 7" 5.2222572 v/ Jan. 31, 1939. I L EfRusH 2,145,530

ELECTRIC TREMULANT ATTACHMENT FOR ACCORDIONS Filed Aug. 9, 1937 2Sheets-Sheet 2 70 n W A Patented Jan. 31, 1939 UNITED STATES PATENTOFFICE Lester E. Rush, Great Falls, Mont.

Application August 9,

6 Claims.

This invention relates to an electric tremulant attachment foraccordions which will automatigally cause the notes to sound with atremulous one.

It is an object of the invention to provide an attachment of theabove-mentioned character which may be installed in the conventionalaccordion without material alterations and which embodies means foreliminating the tremulous effect at the will of the operator.

A further object of the invention is to provide an attachment of theabove-mentioned character which is simple and durable in construction,reliable and efiicient in operation and inexpensive to manufacture.

Other objects and advantages of the invention will be apparent duringthe course of the following description.

In the accompanying drawings, forming a part of this specification andin which like numerals are employed to designate like parts throughoutthe same,

Fig. 1 is an end elevation of an accordion, partly in section, with theattachment installed therein,

Fig. 2 is a perspective View of the accordion and attachment in separaterelation,

Fig. 3 is a side elevation of the attachment, showing the motor mountedwithin the frame of the attachment,

Fig. 4 is a side elevation of the opposite side of the attachment withthe motor mounted outside the frame,

Fig. 5 is a section taken on line 55 of Fig. 4,

Fig. 6 is a detail perspective view of the switch mechanism foroperating the free port valves,

Fig. 7 is a perspective view of the tremulant valve, and,

Fig. 8 is .a fragmentary longitudinal section of the tremulant valve.

In the drawings, wherein for the purpose of illustration I have shown apreferred embodiment of my invention, the numeral 5 denotes aconventional accordion in its entirety having the usual bellows 6, withcompartments 1 and 8 on opposite sides thereof containing the bass andtreble reeds respectively.

Referring more particularly to my invention, the attachment consists ofa partition 9 surrounded by a frame ID adapted to be installed betweenthe bellows 6 and treble compartment 8 of the accordion. The partition 9is composed of two separable boards and a bore H is formed between thepartition boards to extend longitudinally of the partition adjacent itslower edge, the

1937, Serial No. 158,250

bore being provided with opposed openings l2, at spaced intervalsthroughout its length, providing air passages through the partition. Atubular valve casing I3 is fixed within the bore l I having a series ofspaced openings I 4 corresponding to 5 the openings l2 and adapted toregister therewith. A rotary valve of tubular construction is mounted torevolve within the casing 13 having opposed openings H5 at spacedintervals adapted to register with the openings l4 upon 10 rotation ofthe valve and disposed within the valve between the openings [6 areplugs I! to prevent whistling and air leakage. The solid portion of thevalve which passes the openings I4 is slightly narrower in width thanthe openings 15 I4, so that at no time is the opening completely closed.The rotary valve extends beyond the ends of the casing I3 and is securedtherein by means of a jam cap l8 aflixed to the end of the valve by aset screw Ill. The opposite end of the rotary valve carries a gear wheel20 which meshes with the worm 2| formed on the shaft 22 of the electricmotor 23, the free end of the motor shaft being journaled in the bearingclamp 24. The motor 23 is mounted on the partition either 25 beyond theframe H], as shown in Fig. 2, or may be mounted on the partition withinthe frame, as shown in Fig. 3. The motor is connected to a suitablesource of electric current by the wires 25 and interposed in the circuitof the motor is a rheosta-t 26 by means of which the speed of the motoris regulated.

A series of spaced free air ports 21 extend through the partition 9adjacent its upper edge which are normally closed by valve plates 28covered with a lining of soft leather 29. The valve plates are connectedto arms 30 extending from the shaft 3| journaled in the bearing brackets32 attached to the partition. A series of U-shaped loops 33 extend fromthe shaft 3| at spaced intervals, the end loops being engaged by theleaf springs 34 affixed to the partition, which hold the valve plates inclosed position. The intermediate loop is disposed in the path ofmovement of the cam face 35 of the disk wheel 36 mounted on one end ofthe shaft 31 which is journaled in the upper side member of the frameID. A crank arm 38 is attached to the opposite end of the shaft 31 whichis connected by means of the rod 39 to the slide lever 40 slidablymounted in the outer face of the upper side member of the frame I0 andby moving the slide lever the wheel 36 is turned to bring the cam face35 into engagement with the intermediate loop 33 on the shaft 3|,thereby rocking the shaft to swing the valve plates 26 to an openposition.

In operation, the tremulant attachment is easily installed in theconventional accordion by separating the treble compartment from the belows and inserting the frame [0. Upon starting the electric motor 23 therotary valve I5 is revolved at a pre-determined speed causing apulsating current of air to pass through the openings [2 when thebellows are actuated and thus cause the treble reeds to sound with atremulous tone. When it is desired to eliminate the tremulant effect,the slide lever 40 is moved to turn the Wheel 36 so as to rock the shaft3| to open the valve plates 28 and allow a free flow of air through theports 21 which changes the tone of the reeds from a tremolo to a plaintone without having to stop the motor. Thus, itis seen the tremulanteffect may be brought into operation or eliminated at the will of theplayer.

It is to be understood that the form of my invention herein shown anddescribed is to be taken as a preferred example of the same and thatcertain changes in the shape, size and arrangement of the parts may bemade without departing from the spirit of the invention or the scope ofthe subjoined claims.

Having thus described my invention, I claim:

1. A tremulant attachment for accordions comprising a partition adaptedto be inserted between the bellows and treble reeds of an accordion,said partition having a central longitudinal bore provided with opposedopenings at spaced intervals, a rotary valve mounted to revolve in thebore of said partition having transverse passages therethrough at spacedintervals, said passages being of a size to permit communication betweenthe opposite openings at all times and means for revolving said valvewhereby the volume of air passing through said openings is varied.

2. A tremulant attachment for accordions comprising a partition adaptedto be inserted between the bellows and treble reeds of an accordion,said partition having a series of spaced passages therethrough, a rotaryvalve intersecting the passages of said partition and having transversepassages therethrough, said passages being of a size to permitcommunication between the passages of said partition and valve at alltimes and means for rotating said rotary valve to vary the volume of'air passing through said passages.

3. A tremulant attachment for accordions comprising a partition adaptedto be inserted between the bellows and treble reeds of an accordion,said partition having a series of spaced passages therethrough, a rotaryvalve intersecting the passages of said partition and having transversepassages, said passages being of a size to permit communication betweenthe passages of said partition and valve at all times, an electric motormounted on said partition and gearing driven by said motor for drivingsaid rotary valve to vary the volume of air passing through saidpassages. 1

4. A tremulant attachment for accordions comprising a partition adaptedto be inserted between the bellows and treble reeds of an accordion,said partition having a series of spaced passages therethrough, a rotaryvalve intersecting the passages of said partition and having transversepassages therethrough, said passages being of a size to permitcommunication between the passages of said partition and valve at alltimes, means for revolving said valve to vary the volume of air passingthrough said passages, a series of free ports through said partition,valve plates normally closing said ports, and manual means for movingsaid valve plates to open said ports.

5. A tremulant attachment for accordions comprising a partition adaptedto be inserted between the bellows and treble reeds of an accordion,said partition having a series of spaced passages therethrough, a rotaryvalve intersecting said passages of the partition and having transversepassages therethrough, said passages being of'a size to permitcommunication between the passages of said partition and valve at alltimes, a gear wheel carried by one end of said rotary valve, a motormounted on said partition, a worm carried by the shaft of said motor andmeshing with said gear wheel, a series of free ports through saidpartition, valve plates normally closing said ports, a shaft connectedwith said valve plates for swinging the plates to open and close saidports and manually actuated means for rocking said shaft.

6. A tremulant attachment for accordions comprising a partition adaptedto be inserted between the bellows and treble reeds of an accordion,said partition having a central longitudinal bore provided with opposedopenings at spaced intervals, a rotary valve mounted to revolve in thebore of said partition having transverse passages therethrough, atspaced intervals, for register with the openings, said passages beingrelatively wider than said openings to permit direct communicationbetween opposed openings at all times and mechanical means for rotatingsaid valve at a predetermined constant speed.

LESTER E. RUSH-

